Non-aqueous electrolyte and electrochemical device comprising the same

Abstract

Disclosed is a non-aqueous electrolyte comprising: an acrylate compound; a sulfinyl group-containing compound; an organic solvent; and an electrolyte salt. Also, disclosed is an electrode comprising a coating layer formed partially or totally on a surface thereof, the coating layer comprising: (i) a reduced form of an acrylate compound; and (ii) a reduced form of a sulfinyl group-containing compound. Further, disclosed is an electrochemical device comprising a cathode, an anode and a non-aqueous electrolyte, wherein (i) the non-aqueous electrolyte is the aforementioned non-aqueous electrolyte; and/or (ii) the cathode and/or the anode is the aforementioned electrode.

The invention claimed is: 
     
       1. An electrochemical device comprising a cathode, an anode and a non-aqueous electrolyte solution, wherein:
 (i) the non-aqueous electrolyte solution comprises:
 (A) a mixture of compounds suitable for producing a solid electrolyte interface (SEI) layer on an electrode, the compounds consisting essentially of:
 (1) an acrylate compound; and 
 (2) a sulfinyl group-containing compound; 
 
 (B) an organic solvent, and; 
 (C) an electrolyte salt; and/or 
 
 (ii) the cathode and/or the anode comprises a SEI layer formed partially or totally on a surface thereof, the SEI layer consisting essentially of:
 (D) a reduced form of the acrylate compound; and 
 (E) a reduced form of the sulfinyl group-containing compound. 
 
 
     
     
       2. The electrochemical device as claimed in  claim 1 , which is a lithium secondary battery. 
     
     
       3. The electrochemical device as claimed in  claim 1 , wherein the acrylate compound is selected from the group consisting of tetraethyleneglycol diacrylate, polyethyleneglycol diacrylate (molecular weight 50˜20,000), bisphenol A ethoxylated diacrylate (molecular weight 100˜10,000), 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, trimethylolpropane ethyoxylate triacrylate, trimethylolpropane propoxylate triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxylate tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and tris[2-(acryloyloxy)ethyl]isocyanurate. 
     
     
       4. The electrochemical device as claimed in  claim 1 , wherein the sulfinyl group-containing compound is selected from the group consisting of sulfites, sulfonates and sultones.